The purpose of this proposal is to continue the study of human chondrosarcoma (and other cartilage tumors) by histologic, ultrastructural, histochemical, biochemical, immunologic and metabolic techniques. Clinical, radiographic and followup data on the patients will be correlated with the biological profile defined by the studies described above and an attempt will be made to determine if one or several of the studies can serve as predictors of clinical behavior. In the ensuing granting period, special emphasis will be placed on analysis of prostaglandin activity; study of xylose metabolism; isolation of soluble tumor associated cell surface antigens; and development of methods of preoperative dilution of human specific antigen antibody in the patient's sera. Ultimately, the biologic and immunological data will be used to choose and study by in vitro techniques, a variety of chemotherapeutic, isotopic and immunologic therapeutic agents for efficacy of treatment.